<p>Scenario: An ecologist who is searching for indicator species to use in a biodiversity status assessment needs to find out if there is enough data available via GBIF to use hummingbirds as indicator species.  This walk-through demonstrates how she can assess occurrence record density (that is, find out how many data records there are) for hummingbirds in North America by plotting results from the GBIF portal on Google Earth.</p>

<p>First, download and install Google Earth. Go to the Google Earth <a href="http://earth.google.com/download-earth.html">download site</a> for files and instructions.</p> 
<p>For more information on using the Google Earth interface, consult the <a href="http://earth.google.com/userguide/v4/">Google Earth User Guide</a>.</p>

<h4>Step-by-step guide:</h4>

<ol type="1"><li> Enter "Trochilidae" into the search box on the <a href="..">Data Portal</a>.
</li><li> From the <a href="../search/trochilidae">search results page</a>, click on "Family: <strong>Trochilidae</strong>" to open the <a href="../species/13143990/">Overview Page</a> for the bird family Trochilidae (hummingbirds).

</li><li> In the <strong>Actions for Trochilidae</strong> box, click on "Download 1-degree cell density overlay for Google Earth".
</li><li> Switch to Google Earth, and open the downloaded file.
</li><li> Rotate the view in Google Earth to see the overlay of occurrences in North America.  
</li><li> Adjust the transparency of the overlay with the slider located below the <strong>Places</strong> section of the left sidebar.  Note that the density of records in each cell is incated by colour-code, as it is on maps that are generated within the GBIF portal.  For explanation, see the <a href="maps">tutorial page on maps in the GBIF portal</a>.
</li><li> To save the layer, right-click on the description in the Places pane within the left sidebar and select <strong>Save to My Places</strong>. </li></ol>

